Sharpener for lawn-mower knives.



No. 722,177. PATENTED MAR. 3, 1903;

G. PARNSWORTH.

SHARPENER FOR LAWN MOWER KNIVES. APPLICATION FILED my 9, 1902.

N0 MODEL.

7/ 1 WV v ITNEESEE- IHV NT'UP Unrrnn Starts PATENT FFlCE.

GEORGE FARNSWORTH, OF EAST PEPPERELL, MASSACHUSETTS, ASSIGNOR, BY DIRECT AND MESNE ASSIGNMENTS, TO DANIEL R. DWYER AND THOMAS F. GRAHAM, OF EAST PEPPERELL, MASSACHUSETTS.

SHARPENER FOR LAWN MOWER KNIVES.

SPECIFICATION forming part of Letters Patent No. 722,177, dated March 3, 1903. Application filed May 9,1902 Serial No. 106,552. (No model.)

To all whom it may con e n: central vertical longitudinal section, partly Be it known that I, GEORGE FARNSVVORTH, in elevation, of a lawn-mower of well-known a citizen of the United States, residing at East construction, the handle of said lawn-mower Pepperell, in the county of Middlesex and being broken off to save space in the draw- State of Massachusetts, have invented new ings. Fig. 2 is a perspective view of myimand useful Improvements in Sharpeners for proved sharpener-board, the holder therefor, Lawn-Mower Knives, of which the following and the means by which said sharpener-board is a specification. and holder are adjustably fastened to the The object of this invention is to provide a handle of a lawn-mower. Fig; 3 isa trans- 10 sharpener for lawn-mower knives which is verse section, taken'on'line33of Fig. 2, illussimple and durable in its construction and trating the manner in which the sharpenerwhich may be easily attached to the handle board is attached to the holder. Fig. 4 is a of any of the lawn-mowers now in use, and; transverse section taken on line at 4 of Fig. 1, further, which maybe adjusted tangentially illustrating the manner of attaching the I5 and radially with relation to the blades of sharpener-board and holder to the angle-iron said lawn-mower in order that the sharpenerby which said sharpener-board and holder are board may be brought to bear against the attached to the handle of a lawn-mower. cutting edges of the knives of said lawn- Like numerals refer to like parts throughmower with more or less pressure, and, furout the several views of the drawings.

20 ther, may be adjusted tangentially, so that In the drawings, 7 7 7 are rotary lawnthe entire sharpening-surface of said sharpmower knives fast to a rotary frame 8, said ener-board may be brought to bear against frame being fast to the shaft 9, rotated by the cutting edges of said knives, and thus mechanism contained within the casing 10. utilize all of said surface. The handle 11 of the lawn-mower is provided 25 The invention consists in a sharpener for with side pieces 12, pivoted at 13 to the caslawn-mower knivescomprising a sharpenering 10, all in a manner well known to those board, a holder upon which said sharpener skilled in the art. The sharpener-board 14 board is supported, springs interposed 'beextends transversely of the lawn-mower and tween said sharpener-board and holder, and is provided with a sharpening-surface of 30 means to fasten said holder to the handle emery or other desirable sharpening material of a lawn-mower, all constructed and ar- 15. Said sharpener-board has rigidly fasranged in such a manner as to be supported tened thereto two bolts 16 16, said bolts exupon said handle and adjustable lengthwise tending vertically from the sharpening-surthereof. face thereof through holes provided in the 5 The invention again consists in the instrusharpener board holder 17. Between the mentalities hereinbefore set forth, together sharpener-board 14. and the holder 17 and enwith means for adjusting said sharpenercircling each of the bolts 16 are spiral comboard and holder tangentially and radially pression-springslS. Said springs tend to push with relation to said lawn-mower-knives, said the sharpener-board away from: the holder 17 0 means consisting of an angle-piece, one arm and against the cutting edges of the knives 7. 0 of which is fast to said holder and the other Upon the bolts 16 and upon the opposite adapted to be fastened to the handle of a side of the sharpener-board holder to that lawn-mower in such a manner as to be supupon which the spiral springs 18 are located ported upon said handle and adjustable are adjusting-nuts 19, which bear against 5 lengthwise thereof. washers 20. Said washers lie against the rear 9 g The invention finally consists in the comface of the sharpener-board holder 17. The bination and arrangement of parts set forth object of the nuts 19 is to adjust the sharpin the following specification, and particuener-board 14 toward and away from the cutlarly pointed out in the claims thereof. ting edges of the knives 7. By turning the 50 Referring to the drawings, Figure 1 is a adjusting-nuts toward the right the bolts 16 mo and the sharpener-board 14:, to which said bolts are fastened, will be drawn away from the knives 7, and by turning the said nuts to the left the said sharpener-board will be carried toward the knives 7 by the springs 18.

It will be seen that by means of the adjusting-nuts 19 and bolts 16, hereinbefore described,one end of the sharpener-board 14: may be brought nearer to the holder 17 than the other end thereof, so that if, when the device is fastened to the handle of a lawn-mower, one end of the sharpener-board touches the knives and the other end does not the latter end may be adjusted by screwing the nut 19 in the proper direction at the end of the board which does not touch the knives until the sharpener-board 14 comes in contact with said knives.

The holder 17 is fastened to an angle-piece 21 by a bolt 22, fast to said sharpener-board holder and extending through a slot 23, formed in the arm 24 of said angle-piece 21, and having a lock-nut 25 and washer 26 thereon, by means of which the sharpener-board holder-17 is clamped to the slotted arm 24 of the angle-piece 21. The portion of the bolt 22 which passes through the slot 23 and holder 17 is square in cross-section to prevent said holder from turning upon said bolt and also to prevent said bolt from turning in the slot.

23. The arm 27 of the angle-piece 21 is fastened by bolts 28 to a wooden clamp-piece 29, and the said wooden clamp-piece is provided with pointed brads 30, which project downwardly into the upper face of the handle 11, when said clamp-piece is clamped against the upper surface of said handle by means of the screw-clamps 31.

The operation of my improved device for sharpening lawn-mower knives is as follows: Assuming the knives 7 to be rotating in the direction of the arrow, Fig. 1, the cutting edges of said knives pass across the sharpening-surface 15 upon the sharpener-board 14 and are sharpened thereby. The sharpenerboard 14 may yield to varying inequalities in the knife-blade by means of the springs 18 yielding and allowing said sharpener-board to move toward or away from the knives. If it is desired to adjust the sharpener-board slightly with relation to the edges of the knives, it may be done by means of the nuts 19 and bolts 16, as hereinbefore described. If it is desired to adjust the sharpener-board tangentially with relation to the knives in order that all portions of the surface 15 may eventually be brought into contact with the cutting edges of said knives, the sharpenerboard and its holder may be so adjusted simultaneously by means of the bolt 22 and nut 25-viz. by loosening the nut 25 and moving the bolt 22 up or down,as desired, in the slot 23 in the angle-iron 21-and after having moved said sharpener-board to the desired location the holder is clamped to the arm 24 by means of the nut 25 and bolt 22.

A still further means of varying the pressure of the sharpener-board against the knives consists in pressing downwardly upon the handle 11 of the lawn-mower, and as said handle is pivoted through the side pieces 12 at 13 upon the casing 10 it will be seen that by moving the handle 11 downwardly the sharpening-surface 15'will be brought nearer to the cutting edges of the knives, and by moving upwardly on said handle 11 said sharpening-surface will be moved away from said knives. If desirable, a still greater resiliency may be given to the device by making the angle-piece 21 of spring metal, so that the arm 24 can yield to a greater or less extent. After the sharpener-board 14: has been adjusted by means of the nuts 19 and bolts 16 to a correct position touching the cutting edges of the knives, if it is desired to move said sharpener-board and holder bodily away from said knives without changing the relation of the sharpener-board to the holder it may be done by loosening the clamp 31 and moving the clam p-piece 29 and angle-piece 2'1 lengthwise of the handle 11 of the lawnmower. This adjustment lengthwise of the handle of the lawn mower will move the sharpener-board and its holder-board radially with relation to the lawn-mower knives, and this movement may be of sufficient extent to move the sharpener-board entirely out of contact with the knives when it is not desired to use the same and still the relative position of the sharpener-board to the holder remain the same. When it is desired to again place the sharpener-board in contact with the knives, it may be done by moving the clamp-piece 29 and angle-piece 21, attached thereto, lengthwise of the handle 11. It will be seen that the sharpener-board 14 and the holder 17 will thus be moved bodily away from the knives or toward them in a radial direction and also that said sharpener-board and holder may be moved tangentially to said knives without having the relative position of said boards to each other changed by means of the lock-nut 25 and bolt 22, as hereinbefore described. It will thus be seen that the operation of ad justing the sharpener-board tangentially or radially with relation to the knives is very simple andeasily accomplished.

Having thus described my invention, what I claim, and desire by Letters Patent to secure, is-

1. Asharpener for lawn-mower knives comprising a sharpener board, a holder upon which said sharpener-board is supported, and means to fasten said holder to the handle of a lawn-mower in such a manner as to be supported upon said handle and adjustable lengthwise thereof and radially with relation to said knives.

2. A sharpener for lawn-mower knives comprising a sharpener-board, a holder-board, a bolt fast to said sharpener-board at each end thereof and extending through said holderboard, nuts upon said bolts by means of which one end of said sharpener board may be brought nearer to said holder than the other end thereof for the purpose specified, and a spiral spring encircling each of said bolts be tween said holder and sharpener boards.

3. A sharpener forlawn-mower knives comprising a sharpener board, a holder upon which said sharpener-board is supported, and an angle-piece, one arm adapted to be fastened to the handle of a lawn-mower and adjustable lengthwise of said handle and the other arm adj ustably fastened to said holder.

4. Asharpenerforlawn-mowerknivescomprising a sharpener board, a holder upon which said sharpener board is supported, springs interposed between said sharpenerboard and holder, and an angle-piece, one arm adapted to be fastened to the handle of a lawn-mower and adjustable lengthwise of said handle, and the other arm fast to said holder.

5. Asharpenerforlawn-mowerknives,comprising a sharpener board, a holder upon which said sharpener board is supported, springs interposed between said sharpenerboard and holder, at clamp-piece adapted to be clamped to the handle of a lawn-mower and adjustable lengthwise of said handle, an angle-piece, one arm fastened to said clamppiece, the other arm provided with a slot extending lengthwise thereof, a bolt fast to said holder extending through said slot, and a clamp-nut upon said bolt for the purpose specified.

In testimony whereof I have hereunto set my hand in presence of two subscribing witnesses.

GEORGE FARNSWORTH.

Witnesses:

WILLIAM H. MULLIN, NELSON CARTER. 

